Darn Tough Vermont Women's Larisa Light Cushion Socks Nylon, Merino Wool, Lycra, Spandex Performance fit, fine gauge knitting for unprecedented durability Fast action wicking pulls moisture away from the skin, fast drying All-weather performance, naturally antimicrobial - repels bacteria and odor, guaranteed for life Merino wool -the ultimate fiber for breathability and comfort in all conditions True Seamless undetectable seam fusion for an ultra smooth, invisible feel